This invention relates to a vertical lift assembly for use in raising an object, and particularly for use as a diverting assembly for a roller conveyor system.
With increasing automation of manufacturing and warehousing operations, conveyors are becoming ever more relied upon for high-speed, reliable transfer of goods. Often, continuous manufacturing processes turn out goods faster than subsequent processing and finishing stations can perform. In order to accommodate this mismatch, diverting conveyors are used, for example, to distribute the product from the output conveyor of a fast stage to a number of input conveyors of subsequent slower stages. In such applications the lateral transfer to slower conveyors can cause jams on the faster conveyor due to the longer time required to effect the lateral transfer relative to the transit time of the goods on the faster main conveyor. In addition, the need for faster, more facile diverting conveyors requires a self-contained unit that can be fitted to operate compatibly with existing conveyor installations. Typically, conventional diverting systems are built-in to the existing conveyors, and are usually not designed to be added as auxiliary or peripheral equipment.
Diverters of many types are well known to the conveyor art. A typical diverter provides a transfer mechanism, such as a group of transfer belts, which is recessed beneath a transfer surface of the main conveyor when diversion is not desired, and that is raisable above the surface of the main conveyor to engage objects when diversion is intended.
In some conventional diverters, wherein rollers or belts are raised above a conveying surface of a main conveyor, the transfer belts, or the belts used to power rollers if diverter rollers are involved, are stretched during the raising or lowering. This can cause stress to the belts, with an increased chance for failure. Further, it can create difficulties in controlling the rate of speed of the diverting rollers.
Many past devices have involved transfer belts or rollers that are mounted in a frame system in such a manner that when they are raised they are also tilted somewhat. That is, an end of the diverter on one lateral side of the conveyor is raised higher than the end at the other side of the main conveyor during diverter operation. This may be inefficient and may cause tilting of objects being diverted, which may be undesirable in certain instances. Generally, conventional devices have not satisfactorily solved the problem of having vertical lift with no substantial tilting and without stretching of the transfer belts or drive belts for diverter rollers.
In addition, conventional diverters may have a multitude of moving parts and may need to be manufactured to fine tolerances for operation, both of which will tend to increase the cost of such systems. Generally, it is desirable to produce a diverter system that is not only well adapted for nearly universal application but which is also relatively inexpensive to build and operate by comparison to most conventional systems. Further, it is preferable that such a system be constructed to permit relatively easy access for maintenance, be relatively free from problems of failure during use, and minimizes the tilting of the lateral transfer belts and maintains the diverting transfer surface in planar relation with the conveying surface during diversion.